This patch set for 2.6.10-rc3-bk10 (*) generalizes the prio_treecode such that other subsystems than just VMA can use it.

(*) I'm not sure which tree is the most useful base for this. Should I use 2.6.10-rc3-mm* instead of -bk* ? (Or is it already too late for 2.6.10 anyway ?)

While there are currently no other in-tree users than VMA,the prio_tree algorithm will be useful for detecting overlappingdisk IO requests, which is a prerequisite for efficient handlingof barriers, which - besides being a good idea in general - inturn is a prerequisite for useful disk IO priorities.

The three patches that follow are incremental and must be appliedin the order specified.